Concerned with software or hardware firewalls

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5k views

windows firewall turns OFF automatically

It seems pretty weird but for some reason, the Windows 7 firewall turns off. After I turn the firewall on in the control panel, it seems that it turns itself off when I go back to the control after I ...
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2answers
4k views

IPTables default security rules for a gateway/router?

On a router such as dd-wrt or tomato, what would be some default iptables rules? I am asking for rules on a router/gateway - For example; blocking SYN flood attacks, or XMAS attacks. The basic ...
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2answers
237 views

Google DNS in Firewall logs

I was viewing my firewall logs and come across the IP 8.8.8.8. Further check reveals it belongs to Google DNS. And such traffic has been going out from some of our LAN segment PCs. From here on, how ...
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3answers
1k views

How to prevent attacks to server

I have 3 CentOS server configured for my applications. Recently I recognized that there is so many attacks to my servers. I have so many logs about attempt to login to my servers using sshd from ...
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2answers
125 views

Expose the source code repository externally or allow VPN access?

To allow third party consultants, offshore developers and contractors working on the code, we can expose our Git repository externally. Or we can grant VPN access to the external parties and limit ...
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3answers
726 views

iptables: plaintext password protection

I'd like to find a way to block or restrict my access to the web-pages where my password is sent as a plaintext on the internet. Let's assume if I have the same password for all web-pages, is it ...
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3answers
1k views

Why block network ports?

There was another good question here on why you should block outgoing traffic: Why block outgoing network traffic with a firewall? But I was hoping to get an answer on why it is a good idea to block ...
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2answers
3k views

How to block network scans with pfsense?

I am using pfsense as firewall, and I would like to know how I can stop network scans from enumerating open services and ports. Thanks
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1answer
640 views

How can the Google web crawler bypass portals?

This is a situation that I have encountered on a number of occasions. I will conduct a web search in Google, a link to a file (.pdf for example) will take you to that file on the server. It opens up ...
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2answers
254 views

Are there “LAN IPs” on the internet?

I have a home-made web application and thought that an easy way to secure it's administration interface would be to simply reject all IPs that arent from 192.168... Is this viable? is it possible for ...
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2answers
2k views

Benefits of REJECT over DROP on a single PC

Recently I learned about the difference between DROP and REJECT in a firewall. I understand that REJECT is better because it closes the connection immediately instead of waiting for timeout as DROP ...
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2answers
3k views

IPTables DDoS protection working with per client IP address counter AND UDP

I am looking to protect LAMP server with a software, which will detect above average number of requests from single IP numbers (in this case DNS queries), and add these hosts to IPTables deny chain. ...
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1answer
222 views

Maximum protection on a computer network?

I would like to secure as much as possible a computer I am using to sync sensitive data files from work to my home pc. The syncronisation is being done by only 1 software is there a firewall to allow ...
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2answers
1k views

Why is my firewall blocking on some files but not others?

I'm behind a corporate firewall which restricts access to certain urls and most downloads. The download restriction is mainly on .exe(but it allows some exe files to be downloaded and I don't know ...
2
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1answer
50 views

Terms for input/output to and from a Firewall

Is there an official/standard term for the stream of data sent into or out of a firewall? Obviously the inbound traffic would be the traffic under surveillance, and the outbound traffic would be the ...
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5answers
939 views

Firewall rules by URL

is there a solution to create FW rules by URL instead of IP for inbound traffic? For example a.example.com and b.example.com are the same IP on the DNS, but they are different sites, is there a ...
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2answers
467 views

how to find out if a program sends data to internet (without permission)?

We have an application to save our customers data (some kind of CRM). This application has been written in Delphi and is a client/server application. This program apparently is sending out ...
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1answer
1k views

Incoming Packet From Source Port 80

I'm sure no daemon or browser is using network resources, but I found incoming packets from Wireshark: 98.126.43.174 source port 80 --TCP--> MyIp destination port 339 [SYN, ACK] 98.126.43.174 ...
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1answer
201 views

Consequences of using -s and -d arguments in iptables

We are studying iptables for a Computer Systems Security course. We are confused as to what happens when the -s and -d arguments are both used in the same rule, such as: iptables -A OUTPUT -s ...
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2answers
502 views

Enterprise IDS - Deployment & Uses

I am investigating deploying the Snort IDS for an enterprise environment. This environment consists of a NOC that manages several servers, mainly internal but some internet facing. There are several ...
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2answers
552 views

Why wouldn't the reverse shell connect back using the same port that exploited the server?

The reverse shell payload from msf use a new port to connect back to the attacker, therefore if the target server has outgoing filters, attack would fail. i.e established server:ftp <-> ...
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3answers
1k views

Firewall Migration: NetScreen NS500 to FortiGate [closed]

I have recently been tasked with doing a firewall migration from an old NetScreen NS500 box to a FortiGate device (I believe it will be a 60C). I am sure most of you aware that NetScreen boxes are no ...
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2answers
31 views

Profile applications from traffic analysis

I'm investigating options for segmenting a less secure business unit behind a Cisco 5505. I want to take this action quietly and transparently for political reasons. I want to know if it is possible ...
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3answers
199 views

Most secure location of database

Let's say I have a straight forward completely database driven web site application and I store my database on my web server in the DMZ. I won't be broadcasting the IP address of my database because I ...
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1answer
88 views

Do the firewall hardware specifications have to be better than the network it protects?

If I need a bodyguard I'll have to hire someone whose muscles are much tougher than mine. If a server can't handle a DoS/DDoS attack because it consumes it's resources does this mean the firewall has ...
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1answer
118 views

Best practice in securing a web server and an offsite worker

Suppose I'm hosting a web server and a separate box offsite that crunches data. The web server interacts with the worker using the worker's API over port 2888. What would be the design of a secure ...
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3answers
372 views

Where to place a vulnerability scanner within a data center

There is currently a debate in my office on the best location to place a vulnerability scanner (a distributed scanner - Rapid7 Nexpose, using scan engines) within a data center. I see two options: ...
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1answer
45 views

Virtualisation: security on the host side

Virtualised environments are focused on isolating the guest OS. Using the VirtualBox model, the guest might be behind a virtual NAT and/or talk only with other VMs via internal networks, and only ...
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3answers
503 views

Suspicious VMWare connections that bypass firewall

I'm running VMWare 5 and I have found that when I start up VMWare I see two connections: TCP 10.100.100.161:55555->as-40816.engx.vmware.com:https (ESTABLISHED) TCP ...
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1answer
317 views

How are IaaS Virtual Machines Isolated?

I am currently examining Hypervisor firewalls for my graduate thesis, but I unfortunately don't have a lot of experience with IaaS environments. How are IaaS Virtual Machines network isolated from ...
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1answer
1k views

Why are some ports reported as closed by nmap?

I was scanning a machine from inside the same LAN which is running and up to date Windows XP Home Edition which I suspect may be running some malware. The target machine has an up to date antivirus ...
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2answers
3k views

What is more risky? Database Server in DMZ or Trusted Network?

Hoping this is not a dupe of any of the related database / DMZ questions, but I don't think any of them answered my question sufficiently. Assume the following A web server is being used for ...
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1answer
10k views

How does pfsense block torrent traffic?

I know that pfsense is a very effective tool for restricting bit torrent traffic. I was wondering how it actually manages to do that ? There's not much information available on this. The more ...
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3answers
8k views

Config Server Firewall: What Outgoing ports need to be open for wget and apt-get install?

I am just configuring CSF and I have to specify my outbound ports here. I am trying to close as many as possible leaving only what I need open, however what do I need to leave open for wget? # Allow ...
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2answers
251 views

Project help required by a newbie!

Basically, I'm doing a degree in network computing and am currently working on my dissertation right now. I am not an expert with networking yet, so I'm kind of struggling to get started with my topic ...
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3answers
57 views

Utility to build IP exclusion list? [closed]

Are there any utilities out there that can assist in building an IP exclusion list? Scenario: Recently suffered a brute force attack where 50000 failed login attempts came from a multitude of ...
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2answers
191 views

Connecting trusted and untrusted networks

We have two domains that are isolated. First domain is the Corp LAN, the second is an hostile untrusted network with untrusted clients that could contain malware. Clients on the untrusted network ...
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4answers
98 views

Do I need antivirus for this unusual installation - or just firewall?

I'm donating an old Windows XP laptop to a school. The machine will spend its golden years doing only one thing - a process that consists of just three steps: Recording lectures and discussions ...
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1answer
70 views

Which IPTables chains should I log from a security perspective

So far I've always been logging the INPUT and OUTPUT chains because I only used iptables as host firewall. Now I'm configuring network firewall which uses iptables, but I don't know whether I should ...
2
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1answer
2k views

Expose web service in a secure manner

Requirement I have a web service I need to expose on the DMZ for external communication. The web service communicates directly with a critical database that sits on an internal net. Current ...
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3answers
154 views

State before getting whitelisted?

There is a data flow of incoming files (from untrusted, external sources), that get whitelisted by a kind of application layer firewall. Is there a common name for the state of the files before they ...
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1answer
263 views

What security risks are involved with sending data over the internal network on Rackspace Cloud servers?

What are the risks involved with sending unencrypted data over the internal network with Rackspace Cloud Servers? Assume the interfaces use iptables to filter IPs and ports so they only accept data ...
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2answers
514 views

Anomaly based web application Firewall

How practical are anomaly based web application firewall in mitigating web based attacks ? Which types of threats do they mitigate against and which don't they? Are their any practical implementation ...
2
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2answers
62 views

Preventing active OS fingerprinting with iptables

I'm studying network security on my own and I have a few basic theoretical questions here. Would dropping every incoming packet at the network layer be enough to prevent active OS fingerprinting? I ...
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1answer
1k views

Understanding OpenWRT LuCI Firewall Routing with VPN

I'm still fairly new to networking, and I'm having a little trouble grasping some concepts of the proper firewall rules I need to implement for my desired setup. I'm setting up a router with OpenWRT ...
2
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1answer
157 views

Understanding nmap output / author explanation …(Scapy)

I just read this example and explanation (below) in the OReilly book Security Power Tools (2007) in section 6.3 that is written by the creator of Scapy, Philippe Biondi. I think the example is very ...
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1answer
677 views

Using Linux iptables to implement a stateless, packet filtering firewall

When I began my career in network security, almost a decade back, the industry standard was stateful firewalls that even had the ability to inspect some application layer protocols. I had only heard ...
2
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1answer
79 views

Should reverse connections be used to bypass NATs?

I'm planning on doing a demonstration on how remote administrative tools work for my schools computer security club. I plan on writing a RAT in C++ and demonstrating/explaining how it works. I ran ...
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1answer
162 views

Is it possible to track the email sent via BCC List using firewall or network security software?

I want to know whether is it possible to know the conversation/email sent via BCC can be identified by admin in some corporate companies? I have heard that email sent from BCC cannot be identified, ...
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1answer
545 views

IPS/IDS and Firewall Solution(s) to a Small Office

I was tasked with implementing a network security solution for a small real estate agency. They are a typical old-school mom and pops shop, about 15 employees with basic file sharing, printing, and ...